In recent years, so-called digital cameras (image sensing apparatuses) which can sense an image and can convert the sensed image into digital image data by a simple operation have been popularly used. When an image sensed by such camera is printed and is used as a photo, it is a common practice to temporarily input the sensed digital image data from the digital camera to a PC (personal computer), to apply an image process to that digital image data in that PC, and to output the digital image data from the PC to a color printer, which prints out that image.
By contrast, in recent years, a color print system which can directly transmit digital image data to a color printer to print it out without the intervention of any PC, a so-called photo-direct (PD) printer which can directly receive a memory card that is mounted on a digital camera and stores sensed images, and can print sensed images stored in that memory card, and the like have been developed.
On the other hand, many techniques for improving the image quality upon outputting images sensed by a digital camera have been disclosed. For example, as described in Japanese Patent Laid-Open No. 2000-13625, a scheme for correcting any white balance deviation, contrast drop, and the like, which have occurred upon sensing an image by a digital camera, and improving the image quality upon outputting that image is known. This technique extracts the histograms of density, saturation, hue, lightness, and the like of an image, which characterize the image, as individual image feature amounts, and corrects the image to output it more sharply. With this technique, an image with higher image quality can be easily output.
Specifically, when image data is directly transmitted from a digital camera to a printer and is printed out, digital cameras have different specifications, operation methods, and the like depending on manufacturers, the advent of a photo-direct printer apparatus which is compatible to digital cameras of various manufacturers is demanded.
Such photo-direct printer which is compatible to digital cameras for respective manufacturers cannot often interpret function information supplied from an arbitrary digital camera, i.e., often receives a print instruction using a function other than those of the printer apparatus. For example, the size or type of paper sheets designated by a digital camera may often be different from that of paper sheets which are actually set on a printer. In such a case, formation of a print image may be disturbed.